Analysis of Concentration of Heavy Metal (Pb) and Cadmium (Cd) In Waterfish (Eichhornia crassipes) in Indragiri River, Riau

Research has been conducted to determine the concentration of Lead (Pb) and Cadmium (Cd) heavy metals in water hyacinth (Eichhornia crassipes) in the Indragiri River Waters of Indragiri Hilir Regency in May-July 2016. Determination of the research station was carried out by purposive random sampling by considering environmental conditions based on community activities around the river and the existence of Eichhornia crassipes. The main parameters in this study include the concentration of heavy metals Pb and Cd in river water, sediments and Eichhornia crassipes, and physico-chemical parameters as supporting parameters. The results showed that the average concentration of Pb heavy metals in river water was 0.276 ppm and Cd was 0.126 ppm. The average concentration of heavy metals Pb in sediments was 4.61 ppm and Cd of 0.75 ppm. The accumulation of Pb and Cd Eichhornia crassipest heavy metals is included in the low category, namely the average concentration of Pb heavy metals in the root organ is 3.02 ppm, on the leaf stalk 2.61 ppm, and on the leaves 2.09 ppm. The concentration of heavy metal Cd at the root was 0.47 ppm, at the leaf stalk 0.39 ppm, and at the leaves 0.362 ppm. Keyword: Eichhornia crassipes, Pb and Cd heavy metals, water pollution Received 1 November 2019 | Revised 20 December2019 | Accepted 26 January2020


Introduction
The river is one of the water resources that is very important for human life. However, along with the development of various human activities along river waters, it can increase the risk of water quality degradation. The decline in water quality is caused by the entry of waste disposal, which causes changes in the physical, chemical, biological and aesthetic quality of the waters.
This has an impact on the function of waters that are no longer suitable for their purpose in supporting most of the life of aquatic organisms and human needs. Among the dangerous pollutants that can change the quality and damage the carrying capacity of the aquatic environment are heavy metals.The Indragiri River is the largest river in the Indragiri Hilir Regency region, which originates from Lake Singkarak and empties into the Berhala Strait [1].
Indragiri River has a very important function, namely as a means of catching and fish farming, agricultural irrigation, and MCK activities (bathing, washing, toilet). The Indragiri River in the Indragiri Hilir Regency is included in the downstream part of the river and has the potential to receive heavy metal waste originating from activities along the river waters such as domestic activities, gold mining, sand and gravel, the coconut and palm oil processing industry, ports, pathways ship transportation traffic both passenger ships and cargo ships. With this activity, it is possible for pollution by heavy metals, including Lead (Pb) and Cadmium (Cd) heavy metals.
Heavy metals Pb and Cd are heavy metals that are highly toxic to human health. Based on the results of research conducted by Nola Oktaria [2], the concentration of Pb and Cd heavy metals in the waters of the Indragiri River has exceeded the established quality standards. The concentration of heavy metals Pb in the Indragiri River water is 0.99 ppm, while the concentration of heavy metals Cd in the Indragiri River water is 0.17 ppm. According to PP No. 82 of 2001 concerning Management of Water Quality and Water Pollution Control, the permissible concentration of Pb heavy metals for river waters is 0.03 ppm and the permissible concentration of heavy metals Cd is 0.01 ppm. One alternative to evaluating the quality of river waters is to do biomonitoring. Biomonitoring is an environmental evaluation technique using living organisms, by observing levels of pollutants contained in the organism's body tissue to a more specific effect. This method can be used to measure the level of contamination or the level of heavy metal pollution in aquatic ecosystems [3]. The biomonitoring process requires indicator organisms (bioindicators) to determine the level of heavy metal contamination. One type of aquatic plants that can be used as biomonitoring for heavy metal pollution is water hyacinth (Eichhornia crassipes). Eichhornia crassipes is a type of aquatic plant that has a high tolerance to be able to grow well in areas polluted by waste and able to absorb pollutants such as heavy metals Pb and Cd and then accumulate heavy metals in their body tissues. Eichhornia crassipes has the ability as a bioaccumulator that can absorb cations or heavy metal anions contained in wastewater and can grow fast enough and survive in bad conditions [4].

Materials and Methods
This research is an exploratory study through the results of examinations or test samples in the laboratory. The research was conducted at the Laboratory of Chemical Testing and Analysis, Faculty of Engineering, University of Riau in May-July 2016. Samples from the study were river water, sediments, root organs, petioles, and leaves of Eichhornia crassipes. The station was determined by purposive random sampling technique so that 5 research stations were obtained. Samples taken from the five stations are put into a sterile container to be brought to the laboratory. The initial step is to do the sample destruction process and then check the concentration of heavy metals using AAS (Atomic Absorption Spectrophotometer). The data obtained were analyzed descriptively, where the data obtained were presented in the form of dangrafik tables, then compared with the custom values

Lead Heavy Metal (Pb) and Cadmium (Cd) Concentration in River Water and Sediment
The results of measurements of Pb and Cd heavy metal concentrations in river water and sediment at each Indragiri River waters research station Indragiri Hilir Regency can be seen in Table 1. The concentration of heavy metals Pb and Cd on the sediment tends to be higher than in river water. This shows that there is accumulation of heavy metals in the sediments resulting in a buildup in the bottom of the water. Whereas in river water, heavy metals Pb and Cd undergo continuous dilution processes in accordance with the increase in water mass and the current pattern that spreads the heavy metals to other places.
The highest concentrations of heavy metals Pb and Cd in river water and sediment were found at Station V. The high concentration of heavy metals Pb and Cd was due to Station V including the downstream river which has the potential to receive heavy metal waste originating from activities along the river waters. In addition, Station V is a densely populated area and is close to a port that allows high levels of heavy metal waste from Pb and Cd.
Port and transportation activities can contribute to the entry of Pb heavy metal pollution into river waters. Pollution comes from oil dumps, shipyard irons and pipes that have undergone corrosion, batteries or batteries, ballast water discharges, and engine fuel oil emissions.
Darrmono [5] states that Pb heavy metals can enter water bodies through the disposal of ballast water and oil-fuel emissions which are used as anti-knocking addictive substances in the engine.
The heavy metal Pb contained in the fuel oil is then released into the atmosphere through a smoke removal device and then dissolved in water. Cd heavy metal concentrations at Station V are higher when compared to other stations due to corroded pipes and domestic waste disposal such as used cans, plastic waste, batteries, and lubricating oil. This is in accordance with the opinion of Safitri, et al. [6] which states that the source of heavy metal Cd comes from oil and domestic waste such as battery waste and lubricating oil. The lowest concentrations of heavy metals Pb and Cd in river water and sediment were found at Station III. The low concentration of heavy metals Pb and Cd at this station compared to other stations is because Station III is an area far from residential areas and there is no industrial activity so that the contribution of heavy metal entry is smaller than at other stations. Low concentrations of heavy metals Pb and Cd in river water and sediment at Station III are also associated with higher pH compared to other stations and low temperatures (Table 3).
Based on the quality standard determined in PP No.82 of 2001 concerning Water Quality Management and Water Pollution Control, it is known that the concentration of heavy metals Pb and Cd for river water in the waters of the Indragiri River Indragiri Hilir Regency has exceeded the specified quality standard. Based on the quality standard of the range of natural heavy metals in sediments according to USEPA [7], it is known that the concentration of heavy metals Pb and Cd in the sediments of the Indragiri River waters of Indragiri Hilir Regency has not exceeded the specified quality standard values.

Lead Metal (Pb) and Cadmium (Cd) concentrations in Eichhornia crassipes
The results of measurements of heavy metal concentrations of Pb and Cd on Eichhornia crassipes are presented in Table 2.  The process of absorption and accumulation of heavy metals by plants is divided into three processes, namely absorption by roots, translocation, and localization [8]. First, absorption by roots. The mechanism of metal absorption is through the formation of phytokhelatin substances.
Fitokhelatin is a small peptide that is rich in cysteine amino acids that contain S. Atom S in this cysteine which will bind heavy metals from the growing media. Fitokhelatin compounds found in plant roots function to bind the heavy metal elements Pb and Cd and carry them into cells.
Fitokhelatin will form sulfide bonds at the S end of cysteine when it encounters Pb and Cd metals and then forms complex compounds so that Pb and Cd metals will be carried to plant tissues [9].  Table 2 shows that the highest accumulation of heavy metals Pb and Cd is in the root organ.
Metal accumulation is a localization effort carried out by plants, by collecting in one organ. In addition, the high accumulation of metals in the roots caused plants absorb nutrients and metals that are in the water through the roots. The root functions as an absorbent organ and supplies nutrients to other organs. Eichhornia crassipes has fiber roots, so that it has the ability to absorb heavy metals Pb and Cd more and more effectively.

Levels of Lead Metal (Pb) and Cadmium (Cd) Accumulation in Eichhornia crassipes
The level of accumulation of heavy metals Pb and Cd Eichhornia crassipes can be seen from the Bioconcentration Factor. Bioconcentration factor is a comparison between the concentration of metals that accumulate in aquatic organisms and the concentration of metals in the environment (its habitat) in this case river water. The ability of Eichhornia crassipes to accumulate metals in its body is shown as a bioconcentration factor value. This value is obtained by comparing the concentration of similar metals in Eichhornia crassipes samples with river water samples.

1) Bioconcentration Factor (BCF) of Pb metal in Eichhornia crassipes
The results of the calculation of the accumulation of heavy metals Cd on Eichhornia crassipes can be seen from the value of the bioconcentration factor in Figure 1 below.

Figure 1. Bioconcentration Factor Value of Heavy Metal Pb atEichhornia crassipes
From Figure 1, the value of Pb heavy metal bioconcentration factor in the roots of Eichhornia crassipes ranged from 9.71 to 20.00, the leaf stalks ranged from 7.67-15.18, and the leaves ranged from 4.64-9.42. These results indicate that the ability of Eichhornia crassipes to accumulate Pb heavy metals is higher in the root organ, as seen from the higher root bioconcentration factor value compared to the petiole and leaves.
Waldichuck [10], emphasized that the bioconcentration factor value category is BCF <100 = Low accumulation trait, BCF between 100-1000 = Medium accumulation trait, whereas BCF> 1000 = High accumulation trait. Based on the value of the metal bioconcentration factor shown in Figure 1, it can be concluded that the level of accumulation of heavy metals Pb in Eichhornia crassipes belongs to the low accumulative category. The results of the calculation of the accumulation of heavy metals Cd on Eichhornia crassipes can be seen from the value of the bioconcentration factor in Figure 2 below.

Figure 2. Bioconcentration Factor Value of Heavy Metal Cd in Eichhornia crassipes
From Figure 2, the bioconcentration factor value of heavy metal Cd at the roots of Eichhornia crassipes ranged from 2.70-4.82, the leaf stalks ranged from 2.30-4.00, and the leaves ranged from 2.03-3.82. These results indicate that the ability of Eichhornia crassipes in accumulating Cd heavy metals is higher in the root organ, as seen from the higher root bioconcentration factor value compared to the petiole and leaves. Based on the value of the metal bioconcentration factor shown in Figure 2, it can be concluded that the level of accumulation of heavy metals Cd in Eichhornia crassipion belongs to the low accumulative category.

Bioconcentration Factor (BCF) of Cd Metal in Eichhornia crassipes
The results of the calculation of the accumulation of heavy metals Cd on Eichhornia crassipes can be seen from the value of the bioconcentration factor in Figure 2 below.  Figure 2, the bioconcentration factor value of heavy metal Cd at the roots of Eichhornia crassipes ranged from 2.70-4.82, the leaf stalks ranged from 2.30-4.00, and the leaves ranged from 2.03-3.82. These results indicate that the ability of Eichhornia crassipes in accumulating Cd heavy metals is higher in the root organ, as seen from the higher root bioconcentration factor value compared to the petiole and leaves. Based on the value of the metal bioconcentration factor shown in Figure 2, it can be concluded that the level of accumulation of heavy metals Cd in Eichhornia crassipion belongs to the low accumulative category.

Indragiri River Waters Quality
Water quality parameters in this study are physico-chemical parameters which include: temperature, current speed, brightness, pH, DO, substrate texture class, and organic substrate concentration (KOS). The results of water quality measurements for each station in the waters of the Indragiri River region of the Indragiri Hilir Regency can be seen in Table 3.